diff options
Diffstat (limited to 'Documentation/arm/Samsung-S3C24XX/GPIO.txt')
| -rw-r--r-- | Documentation/arm/Samsung-S3C24XX/GPIO.txt | 82 |
1 files changed, 25 insertions, 57 deletions
diff --git a/Documentation/arm/Samsung-S3C24XX/GPIO.txt b/Documentation/arm/Samsung-S3C24XX/GPIO.txt index 816d6071669..8b46c79679c 100644 --- a/Documentation/arm/Samsung-S3C24XX/GPIO.txt +++ b/Documentation/arm/Samsung-S3C24XX/GPIO.txt @@ -1,4 +1,4 @@ - S3C2410 GPIO Control + S3C24XX GPIO Control ==================== Introduction @@ -12,7 +12,7 @@ Introduction of the s3c2410 GPIO system, please read the Samsung provided data-sheet/users manual to find out the complete list. - See Documentation/arm/Samsung/GPIO.txt for the core implemetation. + See Documentation/arm/Samsung/GPIO.txt for the core implementation. GPIOLIB @@ -41,8 +41,8 @@ GPIOLIB GPIOLIB conversion ------------------ -If you need to convert your board or driver to use gpiolib from the exiting -s3c2410 api, then here are some notes on the process. +If you need to convert your board or driver to use gpiolib from the phased +out s3c2410 API, then here are some notes on the process. 1) If your board is exclusively using an GPIO, say to control peripheral power, then it will require to claim the gpio with gpio_request() before @@ -55,7 +55,7 @@ s3c2410 api, then here are some notes on the process. as they have the same arguments, and can either take the pin specific values, or the more generic special-function-number arguments. -3) s3c2410_gpio_pullup() changs have the problem that whilst the +3) s3c2410_gpio_pullup() changes have the problem that whilst the s3c2410_gpio_pullup(x, 1) can be easily translated to the s3c_gpio_setpull(x, S3C_GPIO_PULL_NONE), the s3c2410_gpio_pullup(x, 0) are not so easy. @@ -74,7 +74,7 @@ s3c2410 api, then here are some notes on the process. when using gpio_get_value() on an output pin (s3c2410_gpio_getpin would return the value the pin is supposed to be outputting). -6) s3c2410_gpio_getirq() should be directly replacable with the +6) s3c2410_gpio_getirq() should be directly replaceable with the gpio_to_irq() call. The s3c2410_gpio and gpio_ calls have always operated on the same gpio @@ -105,7 +105,7 @@ PIN Numbers ----------- Each pin has an unique number associated with it in regs-gpio.h, - eg S3C2410_GPA(0) or S3C2410_GPF(1). These defines are used to tell + e.g. S3C2410_GPA(0) or S3C2410_GPF(1). These defines are used to tell the GPIO functions which pin is to be used. With the conversion to gpiolib, there is no longer a direct conversion @@ -120,31 +120,27 @@ Configuring a pin The following function allows the configuration of a given pin to be changed. - void s3c2410_gpio_cfgpin(unsigned int pin, unsigned int function); + void s3c_gpio_cfgpin(unsigned int pin, unsigned int function); - Eg: + e.g.: - s3c2410_gpio_cfgpin(S3C2410_GPA(0), S3C2410_GPA0_ADDR0); - s3c2410_gpio_cfgpin(S3C2410_GPE(8), S3C2410_GPE8_SDDAT1); + s3c_gpio_cfgpin(S3C2410_GPA(0), S3C_GPIO_SFN(1)); + s3c_gpio_cfgpin(S3C2410_GPE(8), S3C_GPIO_SFN(2)); which would turn GPA(0) into the lowest Address line A0, and set GPE(8) to be connected to the SDIO/MMC controller's SDDAT1 line. - The s3c_gpio_cfgpin() call is a functional replacement for this call. - Reading the current configuration --------------------------------- - The current configuration of a pin can be read by using: + The current configuration of a pin can be read by using standard + gpiolib function: - s3c2410_gpio_getcfg(unsigned int pin); + s3c_gpio_getcfg(unsigned int pin); The return value will be from the same set of values which can be - passed to s3c2410_gpio_cfgpin(). - - The s3c_gpio_getcfg() call should be a functional replacement for - this call. + passed to s3c_gpio_cfgpin(). Configuring a pull-up resistor @@ -154,61 +150,33 @@ Configuring a pull-up resistor pull-up resistors enabled. This can be configured by the following function: - void s3c2410_gpio_pullup(unsigned int pin, unsigned int to); - - Where the to value is zero to set the pull-up off, and 1 to enable - the specified pull-up. Any other values are currently undefined. - - The s3c_gpio_setpull() offers similar functionality, but with the - ability to encode whether the pull is up or down. Currently there - is no 'just on' state, so up or down must be selected. - - -Getting the state of a PIN --------------------------- - - The state of a pin can be read by using the function: - - unsigned int s3c2410_gpio_getpin(unsigned int pin); + void s3c_gpio_setpull(unsigned int pin, unsigned int to); - This will return either zero or non-zero. Do not count on this - function returning 1 if the pin is set. + Where the to value is S3C_GPIO_PULL_NONE to set the pull-up off, + and S3C_GPIO_PULL_UP to enable the specified pull-up. Any other + values are currently undefined. - This call is now implemented by the relevant gpiolib calls, convert - your board or driver to use gpiolib. - - -Setting the state of a PIN --------------------------- - - The value an pin is outputing can be modified by using the following: - void s3c2410_gpio_setpin(unsigned int pin, unsigned int to); +Getting and setting the state of a PIN +-------------------------------------- - Which sets the given pin to the value. Use 0 to write 0, and 1 to - set the output to 1. - - This call is now implemented by the relevant gpiolib calls, convert + These calls are now implemented by the relevant gpiolib calls, convert your board or driver to use gpiolib. Getting the IRQ number associated with a PIN -------------------------------------------- - The following function can map the given pin number to an IRQ + A standard gpiolib function can map the given pin number to an IRQ number to pass to the IRQ system. - int s3c2410_gpio_getirq(unsigned int pin); + int gpio_to_irq(unsigned int pin); Note, not all pins have an IRQ. - This call is now implemented by the relevant gpiolib calls, convert - your board or driver to use gpiolib. - -Authour +Author ------- - Ben Dooks, 03 October 2004 Copyright 2004 Ben Dooks, Simtec Electronics |